Detection of Cytochrome C Using a Selective and Sensitive Methylene Blue-Based Electrochemical Aptasensor

Abstract

The present research aimed to detect the cytochrome C using methylene blue (MB)-anchored ultrasensitive electrochemical aptamer conjugated with Au nanoparticles (NPs), as a new electrochemical sandwich immunoassay. Aptamer-Au NPs could act as sandwich amplification element and MB accumulation reagent. According to the results, the interaction of MB and guanine occurred strongly on aptamer probe. After switching the aptamer structure by the cytochrome C, the MB- labeled aptamer probe was forced to detach from the sensing interface. Moreover, the cytochrome C concentrations (0.05-10.0 µM) with 5.0 nM detection limit reduced linearly the peak current of MB. In conclusion, an acceptable selectivity was observed for the constructed aptasensor in detecting the cytochrome C.